Re: [PATCH 6/9] arm: twr-k70f120m: clock source drivers for Kinetis SoC
From: Paul Osmialowski
Date: Wed Jun 24 2015 - 01:12:08 EST
Hi Stephen,
Thanks for the valuable input - all of those points are now on my
checklist for the work on the second iteration of this patchset.
On Tue, 23 Jun 2015, Stephen Boyd wrote:
On 06/23/2015 02:19 PM, Paul Osmialowski wrote:
diff --git a/drivers/clk/clk-kinetis.c b/drivers/clk/clk-kinetis.c
new file mode 100644
index 0000000..dea1054
--- /dev/null
+++ b/drivers/clk/clk-kinetis.c
@@ -0,0 +1,226 @@
+/*
+ * clk-kinetis.c - Clock driver for Kinetis K70 MCG
+ *
+ * Based on legacy pre-OF code by Alexander Potashev <aspotashev@xxxxxxxxxxx>
+ *
+ * Copyright (C) 2015 Paul Osmialowski <pawelo@xxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation.
+ */
+
+#include <linux/clk.h>
Is this using the consumer API? Please remove this include.
+#include <linux/io.h>
+#include <linux/clk-provider.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/err.h>
+#include <mach/kinetis.h>
+#include <mach/power.h>
It would be nice if we didn't need these mach includes so that this
driver can be easily build tested.
+
+#include <dt-bindings/clock/kinetis-mcg.h>
[..]
+}
+
+CLK_OF_DECLARE(kinetis_mcg, "fsl,kinetis-cmu", kinetis_mcg_init);
A clocksource isn't the same as a clk provider. Please split this patch
into two, one for the clk provider (drivers/clk) and one for the
clocksource driver (drivers/clocksource).
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 0f1c77e..1d2ecde 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -106,6 +106,11 @@ config CLKSRC_EFM32
Support to use the timers of EFM32 SoCs as clock source and clock
event device.
+config CLKSRC_KINETIS
+ bool "Clocksource for Kinetis SoCs"
+ depends on OF && ARM && ARCH_KINETIS
Doesn't ARCH_KINETIS imply ARM? Seems that we can drop the ARM
dependency here.
+ select CLKSRC_OF
diff --git a/drivers/clocksource/timer-kinetis.c b/drivers/clocksource/timer-kinetis.c
new file mode 100644
index 0000000..634f365
--- /dev/null
+++ b/drivers/clocksource/timer-kinetis.c
[..]
+
+/*
+ * Clock event device set mode function
+ */
+static void kinetis_clockevent_tmr_set_mode(
+ enum clock_event_mode mode, struct clock_event_device *clk)
s/clk/evt/ ?
+{
+ struct kinetis_clock_event_ddata *pit =
+ container_of(clk, struct kinetis_clock_event_ddata, evtdev);
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ kinetis_pit_enable(pit->base, 1);
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ default:
+ kinetis_pit_enable(pit->base, 0);
+ }
+}
+
+/*
+ * Configure the timer to generate an interrupt in the specified amount of ticks
+ */
+static int kinetis_clockevent_tmr_set_next_event(
+ unsigned long delta, struct clock_event_device *c)
+{
+ struct kinetis_clock_event_ddata *pit =
+ container_of(c, struct kinetis_clock_event_ddata, evtdev);
+ unsigned long flags;
+
+ raw_local_irq_save(flags);
What is this protecting against?
+ kinetis_pit_init(pit->base, delta);
+ kinetis_pit_enable(pit->base, 1);
+ raw_local_irq_restore(flags);
+
+ return 0;
+}
+
+static struct kinetis_clock_event_ddata
+ kinetis_clockevent_tmrs[KINETIS_PIT_CHANNELS] = {
+ {
+ .evtdev = {
+ .name = "fsl,kinetis-pit-timer0",
+ .rating = 200,
+ .features =
+ CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ .set_mode = kinetis_clockevent_tmr_set_mode,
+ .set_next_event = kinetis_clockevent_tmr_set_next_event,
+ },
+ },
+ {
+ .evtdev = {
+ .name = "fsl,kinetis-pit-timer1",
+ },
+ },
+ {
+ .evtdev = {
+ .name = "fsl,kinetis-pit-timer2",
+ },
+ },
+ {
+ .evtdev = {
+ .name = "fsl,kinetis-pit-timer3",
+ },
+ },
+};
+
+/*
+ * Timer IRQ handler
+ */
+static irqreturn_t kinetis_clockevent_tmr_irq_handler(int irq, void *dev_id)
+{
+ struct kinetis_clock_event_ddata *tmr = dev_id;
+
+ KINETIS_PIT_WR(tmr->base, tflg, KINETIS_PIT_TFLG_TIF_MSK);
+
+ tmr->evtdev.event_handler(&(tmr->evtdev));
Unnecessary parentheses, please remove them.
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * System timer IRQ action
+ */
+static struct irqaction kinetis_clockevent_irqaction[KINETIS_PIT_CHANNELS] = {
+ {
+ .name = "Kinetis Kernel Time Tick (pit0)",
+ .flags = IRQF_TIMER | IRQF_IRQPOLL,
+ .dev_id = &kinetis_clockevent_tmrs[0],
+ .handler = kinetis_clockevent_tmr_irq_handler,
+ }, {
+ .name = "Kinetis Kernel Time Tick (pit1)",
+ .flags = IRQF_TIMER | IRQF_IRQPOLL,
+ .dev_id = &kinetis_clockevent_tmrs[1],
+ .handler = kinetis_clockevent_tmr_irq_handler,
+ }, {
+ .name = "Kinetis Kernel Time Tick (pit2)",
+ .flags = IRQF_TIMER | IRQF_IRQPOLL,
+ .dev_id = &kinetis_clockevent_tmrs[2],
+ .handler = kinetis_clockevent_tmr_irq_handler,
+ }, {
+ .name = "Kinetis Kernel Time Tick (pit3)",
+ .flags = IRQF_TIMER | IRQF_IRQPOLL,
+ .dev_id = &kinetis_clockevent_tmrs[3],
+ .handler = kinetis_clockevent_tmr_irq_handler,
+ },
+};
Any reason we can't just use request_irq() instead of having a set of
static irq actions?
+
+static void __init kinetis_clockevent_init(struct device_node *np)
+{
[..]
irq;
+ }
+
+ chan = of_alias_get_id(np, "pit");
+ if ((chan < 0) || (chan >= KINETIS_PIT_CHANNELS)) {
Unnecessary parentheses, please remove them.
--
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